Chapter 9 Managing Inventory in the Supply Chain Inventory is an asset on the balance sheet and inventory cost is an expense on the income statement. Inventories impacts return on asset (ROA) Inventory is important to sales and customer service Inventory is also important to sourcing and production
Inventory in US Economy
Rationale for Holding Inventory Batching Economies Procurement Production Transportation Uncertainty/Safety Stocks All organizations are faced with uncertainty. On the demand side, there is uncertainty in the quantity and timing of customer orders On the supply side, there is uncertainty about getting what is needed from suppliers and order fulfillment time
Rationale for Holding Inventory In-Transit and Work-in-Process (WIP) Stocks Time required for transportation means that even while goods are moving, an inventory cost is incurred. The longer the transit time, the higher the inventory cost. WIP stock inventory cost can be significant while they sits in a manufacturing facility.
Rationale for Holding Inventory Seasonal Stocks Seasonality can occur in the supply of raw materials, in the demand for finished product, or in both. Those faced with seasonality issues are constantly challenged when determining how much inventory to accumulate. Seasonality can impact transportation. Anticipatory Stocks A fifth reason to hold inventory arises when an organization anticipates that an unusual event might occur that will negatively impact its source of supply.
The Importance of Inventory in Other Functional Areas Inventory is more prominent in the interface of logistics with other functional areas Finance (both balance sheet & income statement) Marketing (sales growth, customer service, market share) Manufacturing (production runs, seasonality)
Inventory Costs Inventory Carrying Costs Cost of capital tied up in inventory lost of opportunity from investing that capital elsewhere hurdle rate weighted average cost of capital (WACC).
Inventory Costs Storage Space Cost includes handling costs associated with moving products into and out of inventory, as well as costs like rent, heat, and light Inventory Service Cost includes insurance and taxes Inventory Risk Cost reflects the possibility that inventory value might decline for reasons beyond firm s control
Calculating the Cost of Carrying Inventory Calculating the cost to carry (or hold) a particular item in inventory involves three steps. Step 1, determine the value of the item stored in inventory. Step 2, determine the cost of each individual carrying cost component to determine the total direct costs consumed by the item while being held in inventory. Step 3, divide the total costs calculated in Step 2 by the value of the item determined in Step 1.
Trade Off between Order Cost and Inventory Carrying Cost Order Cost is the expense of placing an order for additional inventory
In-Transit Inventory Carrying Cost Owner of product while it is in transit will incur inventory carrying costs. In-transit inventory carrying cost becomes especially important for global supply chains since distance and time from the shipping location both increase.
Determining the Cost of In-Transit Inventories storage space cost not relevant to inventory in transit insurance needs requires special analysis inventory in transit may incur obsolescence or deterioration costs
The Just-in-Time Approach Four major elements zero inventories short, consistent lead times small, frequent replenishment quantities high quality, zero defects
Vendor-Managed Inventory Basic principles: The vendor and its customer agree on which products are to be managed. An agreement is made on reorder points and economic order quantities for each of these products. As these products are shipped, the customer notifies the vendor by SKU, of the volumes shipped on a realtime basis. The vendor is responsible to ensure timely replenishment and no stock out.
ABC Analysis: Focusing management attention on the important few Application of Pareto s Law, or the 80 20 Rule Many business situations were dominated by a relatively few vital elements Assigns inventory items to one of three groups according to the relative impact or value of the items A items are considered to be the most important B items being of lesser importance C items being the least important
Relationship between Items in Product line and Sales contribution